Tube scraper



-Dec. 14 19-26.

A. MlDDERMANN TUBE SCRAPER Filed June 22, 1925 wwzar Patented Dec: 14, 1926.

UNITED STATES PATENT OFFIC ADOLF MIDDERMANN, OF HOHENLIMBURG, GERMANY, ASSIGNOR T0 JOSEF DAI-ILEN, OF ESSEN-BREDENEI, GERMANY.

TUBE soRArER.

Application filed. June 22, 1925, Serial No. 38,932, and. in Germany May 24, 1925.

To remove deposits from the inner sur face of the wall of boiler :tubes, especially scales, tools are used which roll upon the inner face of the tube walland which are similar to. toothed wheels and sharpened, said tools being adapted to execute in the tool head, besides the rotating movements, radial movements which, owing to the centrifugal action of the tool, make said tool adapt itself to the variations of the inner diameter of the tube due to the removal of the incrustation. By this action of its mass the tool exerts a destroying action upon the incrustation in the boiler tubes. The axles of the tools participate as usual in this radial movement.

The invention consists in the arrangement of three tool bodies approxlmately of sec tor-shaped cross section around the axle of the tool head so that they form togethera cylinder, said tool bodies being guided at their end faces by flat projections engaging with radially directed slots of the inner endfaces of two disks of the tool head, the tools being rotatable in cut out parts of these tool bodies. The axial gaps between the tool bodies vary continuously in consequence of the continuous change in the distance between the tool bodies and the centre of the tool head, said gaps between the tool bodies get Wider or narrower, whereby the settling of particles is prevented.

An embodiment of the invention is shown in the accompanying drawings in which:

Fig. 1 is a vertical section on line A-B of Fig. 3.

Fig. 2 is a front elevation.

Fig. 3 is a horizontal section on line C-B of Fig. 1.

Fig. 4 is a plan view of the top plate seen from below.

The tool head consists of adisk Z) and of an axle a. In the lower surface of disk Z1 a central cavity having a female thread 03 is '7 arranged into which a flexible shaft is to be screwed designed to transmit the rotating movement. On the opposite end of axle a a disk 6 is mounted fixed by means of a nut. In the inner face of disks Z) and c radial slots it are arranged. Tool bodies m of approximately sectonshaped cross section are guided in said radial slots of disks Z2 and e by means of flat projections i.

In the apparatus shown three tool bodies m are arranged which, together, form a cylinder. It is evident, that more than three tool bodies may be used. The tool bodiesm carry on their continuous axles 0, which are secured against rotation, sharp toothed wheels 7) which freely rotate around said axles and are alternately mounted on saidaxles, in a manner known per se.

When the tube cleaner is to be used, it is inserted into the tube to be cleaned and a rapid rotating movement is communicated to it. Owing to the centrifugal force the tools move in outward direction and destroy, by the action of their masses, the incrustation.

As the mass of the tool head participates, according to the invention, essentially in the centrifugal action, the action of the masses is considerably increased and the working process is considerably accelerated.

I claim A tube scraper, comprising in combination a tool head consisting of an axle, a bottom disk having radial slots in its inner surface and made in one piece with said axle and of a top disk having radial slots and fixed on the top end of said axle, the tool bodies of approximately sector-shaped cross section and having radial inwardly directed apertures, flat projections of said tool bodies engaging with said radial slots of the bottom disk and top disk of said'tool head. a vertical continuous axle on each tool body, and tools consisting of toothed wheels having sharp teeth rotatably mounted on said axles of said tool bodies.

In testimony whereof I aflix my signature.

. ADOLF MIDDERMANN. 

